The present invention is directed to an optical subassembly with fibers, particularly for use in fiber communication systems.
There are numerous ways to couple light to and from opto-electronic devices and fibers. One typical manner in which this is achieved is to butt couple the opto-electronic devices right up against the end faces of the fiber. Such butt-coupling requires active alignment to achieve desired levels of coupling efficiency. Further, butt-coupling does not allow the light beam to be modified. Finally, such butt-coupling typically requires close positioning of the opto-electronic devices in accordance with the spacing of the fibers, increasing crosstalk.
Another manner of achieving coupling between fibers and opto-electronic devices is to use short fibers, which in turn are coupled to the fibers. This allows surface emitting opto-electronic devices to be coupled with fibers, but still requires active alignment.
One passive alignment scheme proposed involves providing holes in all of the components to be aligned, e.g., a ferrule housing the fibers, a light coupling device including optics and a substrate including the opto-electronic devices. Pins are then inserted into the holes to realize alignment of all the elements. Such single shot alignment may not be accurate enough for all applications. Further, the materials which can be used for the light coupling device are limited when the holes need to be provided therein. Finally, such alignment requires that there be a linear relationship among all of the components.
The present invention is therefore directed to an optical subassembly which substantially overcomes one or more of the problems due to the limitations and disadvantages of the related art.
This and other advantages may be realized by providing an integrated active optical system including an opto-electronic device, an optics block, and a spacer, separate from the optics block, providing spacing between the opto-electronic device and the optics block, the opto-electronic device, the optics block and the spacer being aligned and bonded together.
The spacer and the optics block may be aligned and bonded on a wafer level prior to dicing. The spacer may surround the opto-electronic device. The system may further include a substrate, both a bottom of the opto-electronic device and the spacer being bonded to the substrate. The opto-electronic device may be bonded to the substrate on a wafer level prior to dicing. A top surface of the opto-electronic device may be bonded to the spacer and the spacer further include interconnection tracks. The opto-electronic device may be bonded to the spacer on a wafer level prior to dicing. The substrate, the optics block and the spacer may all be made of silicon. The system may be surface mounted to an electrical interface.
The opto-electronic device may include at least two opto-electronic devices. The at least two opto-electronic devices may be a light source and a light detector or may be an array of identical opto-electronic devices.
The above and other objects may further be realized by providing a system including a housing having a fiber, an opto-electronic device, and an optics block having two surfaces, each surface having an optical element thereon, the optics block coupling light between the opto-electronic device and the fiber, the housing, the opto-electronic device and the optics block being integrated together.
The opto-electronic device may include at least two opto-electronic devices and the fiber may include at least two fibers. The at least two opto-electronic devices may be separated from each other in at least one direction by more than the at least two fibers are separated from one another. The at least two opto-electronic devices may be separated from each other in at least two directions by more than the at least two fibers are separated from one another in each respective direction. The at least two opto-electronic devices may include a light source and a light detector or an array of identical opto-electronic devices.
The system may further include a spacer block between the optics block and the opto-electronic device. The system may further include a substrate, both a bottom of the opto-electronic device and the spacer being bonded to the substrate. A top surface of the opto-electronic device may be bonded to the spacer and the spacer may further include interconnection tracks.
The optical axis of the fiber and the optical axis of the opto-electronic device may be at an angle. The system may further include a reflective surface directing light between the opto-electronic device and the fiber. At least one optical element on the optics block may homogenize light. The system may be surface mounted to an electrical interface. The optical elements on the optics block may be made on a wafer level.
The above and other objects of the present invention may be realized by providing a system including an opto-electronic device, an optics block having at least one optical element thereon, and a sealing structure surrounding the opto-electronic device, the opto-electronic device, the optics block and the sealing structure being integrated.
The system may be surface mounted to an electrical interface. The system may include a spacer between the optics block and the opto-electronic device. The sealing structure may include a bottom surface of the optics block and the spacer. An optical element may be provided on the spacer.
The system may include a substrate receiving the opto-electronic device therein. The sealing structure may include the substrate and a bottom surface of the optics block. The system may include a spacer block between the optics block and the opto-electronic device. The sealing structure may include the substrate and a bottom surface of the spacer. The substrate may have vias there through connecting the opto-electronic device to other systems. The opto-electronic device may be in contact with the substrate, the substrate serving as a heat sink for the opto-electronic device.
These and other objects of the present invention will become more readily apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating the preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.